Spi 91-355-8 Feeler Gauge Blade 0.0025 in Parallel Leaf

Product Description

The SPI 91-355-8 is a single parallel-leaf feeler gauge blade used for precision gap measurement in mechanical and HVAC service work. The blade measures 0.0025 inches thick, 0.5 inches wide, and 12 inches long, ground from high carbon steel for consistent thickness and durability across the full length of the leaf. Technicians use feeler gauges to verify clearances on valve trains, burner orifice gaps, blower wheel tolerances, compressor reed valves, and general mechanical assemblies where tight dimensional tolerances must be confirmed before and after service.

This blade is suited for trade professionals who need individual replacement leaves or supplemental blades at a specific thickness. The 12-inch parallel leaf format provides uniform width from end to end, making it practical for measuring gaps in confined areas or across wider contact surfaces. Licensed HVAC technicians, refrigeration mechanics, and millwrights commonly use blades at this thickness range when checking fine clearances on compressor valve plates, scroll tip seals, and precision-fit mechanical components.

Key Features

• 0.0025-inch blade thickness for fine-tolerance gap measurement
• Parallel leaf style provides consistent 0.5-inch width along the full 12-inch length
• High carbon steel construction resists flex and maintains dimensional accuracy
• 12-inch length accommodates deep or extended reach applications
• Single-blade format allows targeted replacement without purchasing a full set

Compatibility

Designed as a standard parallel-leaf feeler gauge blade suitable for general mechanical and HVAC service applications requiring a 0.0025-inch gap measurement tool.

Installation Notes

Feeler gauge blades are a hand-measurement tool and do not require installation. Clean blade surfaces before use to prevent debris from introducing measurement error. Do not force a blade into a gap — if resistance is felt, try the next smaller thickness. Store blades flat or coiled loosely to prevent permanent set that would affect calibration accuracy.